/*
 *  Copyright 2009 The Apache Software Foundation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package org.mybatis.generator.logging;

import static org.mybatis.generator.internal.util.messages.Messages.getString;

import org.mybatis.generator.internal.ObjectFactory;

/**
 * Factory for creating loggers. Uses runtime introspection to determine the
 * AbstractLogFactory implementation.
 * 
 * @author Jeff Butler
 * 
 */
public class LogFactory {
	private static AbstractLogFactory logFactory;

	static {
		try {
			ObjectFactory.internalClassForName("org.apache.log4j.Logger"); //$NON-NLS-1$
			logFactory = new Log4jLoggingLogFactory();
		} catch (Exception e) {
			logFactory = new JdkLoggingLogFactory();
		}
	}

	public static Log getLog(Class<?> clazz) {
		try {
			return logFactory.getLog(clazz);
		} catch (Throwable t) {
			throw new RuntimeException(getString("RuntimeError.21", //$NON-NLS-1$
					clazz.getName(), t.getMessage()), t);
		}
	}

	/**
	 * This method will switch the logging implementation to Java native
	 * logging. This is useful in situations where you want to use Java native
	 * logging to log activity but Log4J is on the classpath. Note that this
	 * method is only effective for log classes obtained after calling this
	 * method. If you intend to use this method you should call it before
	 * calling any other method.
	 */
	public static synchronized void forceJavaLogging() {
		logFactory = new JdkLoggingLogFactory();
	}

	private static class JdkLoggingLogFactory implements AbstractLogFactory {
		public Log getLog(Class<?> clazz) {
			return new JdkLoggingImpl(clazz);
		}
	}

	private static class Log4jLoggingLogFactory implements AbstractLogFactory {
		public Log getLog(Class<?> clazz) {
			return new Log4jImpl(clazz);
		}
	}

	public static void setLogFactory(AbstractLogFactory logFactory) {
		LogFactory.logFactory = logFactory;
	}
}
